Polynesian Arrowroot, Pia

Tacca leontopetaloides

Physical Characteristics

Tacca leontopetaloides is an evergreen Perennial growing to 1 m (3ft 3in) by 1 m (3ft 3in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 9. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid and neutral soils and can grow in very acid soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Widely spread in tropical areas, either as a native plant or naturalized, from Africa, through Asia to Australia and the Pacific..

Habitats

Edible Uses

Edible Parts: Root Edible Uses: The root is a rich source of starch. It can be eaten raw or roasted, or the starch can be extracted[301 ]. The tubers have eyes, a pale-yellow skin and dull-whitish flesh, and are usually bitter and almost inedible when raw[429 ]. The starch, called Tahiti (or Fiji) arrowroot, is easy to extract and is used in breads or soups, it can be mixed with papayas, bananas and pumpkins, flavoured with vanilla and lemon, and cooked into poi[301 , 429 ]. Good washing is essential because of the presence of the bitter substance (taccalin) which is said to be poisonous[451 ]. To obtain the starch, the tubers are peeled, grated, and the resultant pulp washed in water several times, finally in a sieve or cloth. The aqueous starch solution is collected and the starch grains allowed to settle out, collected and dried in the sun[429 ]. In cultivated plants the tuber can be 5 - 10cm long, with unconfirmed reports saying that it may reach the size of a coconut[451 ].

Medicinal Uses

Antidiarrhoeal Dysentery Miscellany Skin Stings Polynesian arrowroot is often used in traditional medicine in the Pacific Islands[311 ]. The inside of the root is squeezed in water and applied as a rinse to injured eyes. The starch from the tubers of the plant was used as a remedy for diarrhoea and dysentery[311 ]. The root is also used as a thickener in medical preparations[311 ]. The starch from the root is rubbed onto sores and burns[311 ]. The crushed leaf stalks of the plant are rubbed onto bee and wasp stings[311 ]. The stem is roasted and the sap squeezed out and used in the form of ear drops as a remedy for earache[398 ].

Known Hazards

The untreated root is considered to be toxic in some areas[398 , 451 ].